Sulfur containing organosilicon compounds are useful as reactive coupling agents between rubber and silica fillers providing for improved physical properties. They are also useful as adhesion primers for glass, metals and other substrates.
U.S. Pat. Nos. 3,842,111 and 3,873,489 disclose various sulfur containing organosilicon compounds. These sulfur containing organosilicon compounds are of the formula EQU Z-Alk-S.sub.n -Alk-Z
where Z is ##STR2## where R.sup.1 is an alkyl of 1 to 4 carbon atoms or phenyl and R.sup.2 is alkoxy of 1 to 8 carbon atoms, cycloalkoxy of 5 to 8 carbon atoms; or alkylmercapto with 1 to 8 carbon atoms; Alk is a divalent aliphatic hydrocarbon or unsaturated aliphatic hydrocarbon or a cyclic hydrocarbon containing 1 to 18 carbon atoms and n is an integer of from 2 to 6.
Japanese Application J6 2115045-A discloses rubber compositions containing disulfide compounds of the formula EQU R--S--S--R
where R can be 1-18 carbon allyl, (ar)alkyl or alkanyl optionally substituted with carboxyl, alkoxycarbonyl, N-alkylamido, N-anilinoamide and amino.
U.S. Pat. No. 5,347,015 relates to disulfides of the formula EQU X.sup.1 .paren open-st.CH.sub.2 .paren close-st..sub.n S--S.paren open-st.CH.sub.2 .paren close-st..sub.n X.sup.2
where X.sup.1 and X.sup.2 are identical to one another and are each --Br, --N--phthalimide, --NH.sub.2, --OOC.paren open-st.CH.sub.2.paren close-st..sub.3 COOH, --OSO.sub.2 --CH.sub.3, --NH .paren open-st.CH.sub.2 .paren close-st..sub.2 NH.sub.2, --SO.sub.3 H or --SO.sub.3.sup.- M.sup.+ and n is from 11 to 25 or X.sup.1 is --OH and X.sup.2 is --Br or X.sup.1 and X.sup.2 are each --COO--CH.sub.2 --CH.sub.3 and n is 10 to 25.